CN101228337A

CN101228337A - Direct-action valve lifter for internal combustion engine

Info

Publication number: CN101228337A
Application number: CNA2005800511487A
Authority: CN
Inventors: 永洞真康; 安藤辉明
Original assignee: Nittan Valve Co Ltd
Current assignee: Nittan Corp
Priority date: 2005-08-01
Filing date: 2005-08-26
Publication date: 2008-07-23
Also published as: EP1911940A1; EP1911940A4; KR101011427B1; JP2007040114A; JP4829562B2; WO2007015315A1; KR20080033273A; US20090056659A1

Abstract

A direct-action valve lifter having reduced number of parts and simple structure and capable of being switched to high lift and low lift. [MEANS FOR SOLVING PROBLEMS] The valve lifter is interposed between a cam and a valve stem. The cam (20) has a high lift cam (22) and low lift cams (24) integrated together, and the valve lifter (30) has a side lifter (32) slidingly in contact with a low lift cam, a center lifter (40) slidingly in contact with a high lift cam, and a hydraulic means (hydraulic path)(11b) for sliding the center lifter (40) in order to switch the amount of valve lift between two stages of high and low. A slit (33) for causing the high lift cam to strike at the air is provided at the top of a cylindrical lifter body so that the lifter body functions as the side lifter (32) having low lift cam sliding contact surfaces (32a). A hole (34) orthogonal to the slit (33) is provided in the lifter body, and the piston-type center lifter (40) slid by hydraulic pressure is provided in the hole (34). When the center lifter (40) is at a position corresponding (not corresponding) to the slit (33), it is a high (low) lift mode. In the valve lifter, the number of parts is reduced and the structure is simple, a dimentional tolerance required for each part is relaxed, and work for assembling each part is simplified.

Description

Direct-action valve lifter for internal combustion engine

Technical field

The present invention relates to be installed in the cam of the valve actuating gear that constitutes internal-combustion engine and the columnar direct-action valve lifter between the valve stem, thereby particularly have low lift cam and slip the side tappet of face and have high lift cam and slip the center tappet of face and make it to move the direct-action valve lifter for internal combustion engine that to adjust the lifting capacity of valve by the height two-stage by switching at high lift cam and the incorporate cam of low lift cam unit.

Background technique

As this direct-action valve lifter, disclosed product is understood by people in following patent documentation 1 grade.At this, as shown in figure 11, columnar tappet body 1 be dividing in the top have with low promote with the center cams of the corresponding circle of center cams slip face 2a central part center tappet 2 and have the cylindrical shape side tappet 3 that slips face 3a with the height lifting with the side cam of the corresponding ring-type of side cam at the top, simultaneously, the configuration first connection pin 5a between the through hole 4a, the 4b that stride across center tappet 2 and side tappet 3; The configuration second connection pin 5b between through hole 4b, 4c.Reference character 6 is to make the first connection pin 5a and the second connection pin 5b return back to the spring members of assigned position, and reference character 7 is to be installed between the 3b of spring load portion of the 2b of spring load portion of center tappet 2 bottoms and side tappet 3, to make tappet 2 opposite side tappets 3 in center remain on the spring members of above-below direction assigned position.

And, as long as the first connection pin 5a is in the through hole 4a, then form center tappet 2 and side tappet 3 tappet axially (Figure 11 above-below direction) separates the form (form shown in Figure 11) of (side tappet 3 can sink to respect to center tappet 2), the driving (hanging down lifting capacity) that is produced by center cams passes to tappet body 1 via the face 2a of slipping.On the other hand, utilize oil pressure to make the active force of the first connection pin 5a and the second connection pin 5b antagonistic spring 7, move to Figure 11 right, when the first connection pin 5a becomes across the position between through hole 4a, the 4b (second position of connection pin 5b between through

hole

4b, 4c), become the form that center tappet 2 and side tappet 3 link at the tappet axle direction via the first connection pin 5a and the second connection pin 5b, the driving (high lifting capacity) that is produced by the side cam passes to tappet body 1. via the face 3a of slipping

Patent documentation 1: Japanese Unexamined Patent Application Publication 2002-509219 (Fig. 1, Fig. 2)

, in above-mentioned patent documentation 1, columnar tappet body 1 is the structure of having accommodated center tappet 2, side tappet 3, the first connection pin 5a, the second connection pin 5b, spring portion 6 and spring members 7, and the quantity of component parts is many.

Particularly for this tappet is successfully moved, the position of connection pin and through hole concerns that consistent accurately is indispensable, no matter thereby be the dimensional accuracy of pin 5a, still with the dimensional accuracy of the dimple of connection pin 5a butt or the second connection pin 5b and then be the dimensional accuracy etc. of through hole, the hole shape of tappet body 1 and each component parts that is installed on the tappet body 1 are all required high dimensional accuracy, therefore have the problem difficult, that manufacture cost uprises of producing in batches.

In addition, between center tappet 2 and side tappet 3, because being used to make center tappet 2 is indispensable with respect to the spring members 7 that side tappet 3 remains on the above-below direction assigned position, so (center tappet 2 separates at the tappet axle direction with side tappet 3 in low lifting pattern, side tappet 3 is the form that sinks to of center tappet 2 relatively) down during the high spinning movement of cam, the elastic force of spring members 7 plays a role often, and the sliding friction increase of tappet etc. have the possibility that hinders tappet successfully to move.

Summary of the invention

The present invention proposes in view of above-mentioned prior art problems, its purpose is to provide a kind of direct-action valve lifter for internal combustion engine, it is installed in and makes between high lift cam and low lift cam incorporate cam unit and the valve stem, and the quantity of component parts is few, simple in structure, changeable to be high the lifting and the action smoothly of low lifting ground.

In order to achieve the above object, in the direct-action valve lifter for internal combustion engine of invention first aspect, in the columnar direct-action valve lifter that between the cam of the valve actuating gear that constitutes internal-combustion engine and valve stem, clamps, described cam is by making high lift cam and low lift cam is integrated constitutes, described valve tappet comprises side tappet that described low lift cam slips, center tappet that described high lift cam is slipped, makes the tappet action of described center in order to valve lift amount is switched to the oil sector of height two-stage, wherein:

Be provided with along the slit of the center cams idle running usefulness of cam slide direction extension at the top of described columnar tappet body, be formed in the top and have the side tappet that low lift cam is slipped face, simultaneously, on described tappet body, be provided with along the hole of extending with the direction of described slit quadrature, the piston type center tappet that the configuration using oil pressure slides in this hole.

The oil pressure that the center tappet utilization of (effect) piston type is acted on slides along the hole, and when the center tappet became the position corresponding with slit, high lift cam and center tappet slipped, and transmits high lifting capacity via center tappet and side tappet (tappet body) on valve stem.On the other hand, when the center tappet became not corresponding with slit position, high lift cam dallied in slit, and simultaneously, low lift cam and side tappet slip, and transmit low lifting capacity via side tappet (tappet body) on valve stem.

That is, the center tappet can utilize oil pressure to slide along the hole, selects the form that a ground adopts the form that can slip with center cams and do not slip with center cams.

Thereby, because valve stem is mainly by as the columnar tappet body of side tappet be configured in the piston type center tappet that utilizes oil pressure to slide in the hole of tappet body and constitute, so, to compare component parts quantity few with the many prior art of component parts quantity, the desired tolerance of size of each component parts is loose, and the operation that each component parts is installed also becomes simple.

In addition, owing to unlike prior art, be provided for respect to the center tappet being remained on spring members on the above-below direction assigned position as the tappet body of side tappet, high lift cam dallies in slit in low lifting pattern, add that the elastic force that does not have spring members is as the load effect, so, even under low lifting pattern, can guarantee that also tappet successfully moves during the high spinning movement of cam.

The second aspect of invention constitutes described hole by circular hole in the described direct-action valve lifter for internal combustion engine of first aspect of invention, make described center tappet constitute cylindrical shape.

(effect) since center cams to slip face be arc surface, so the length of the face that slips of the lifting capacity of regulation shortens relatively, the size of center tappet on the cam slide direction reduced etc., the design freedom raising of center cams.

The third aspect of invention makes the slit width of described high lift cam idle running usefulness constitute roughly size with width (thickness of slab) coupling of described high lift cam in the described direct-action valve lifter for internal combustion engine of first or second aspect of invention.

(effect) is between columnar tappet body and the cylinder barrel as its slide relative face, be necessary to be provided with the rotation preventive mechanism of the projection of for example so-called tappet base side that is located at the pod of cylinder barrel side and engages with this pod, but because the slit width of center cams idle running usefulness and the thickness of slab approximate match of center cams, so the profile by prior setting cam so that center cams often be fastened in this slit, thereby the slit of cam idle running usefulness and center cams are as the rotation preventive mechanism performance function that stops the tappet body to rotate relative to cylinder barrel.

By above explanation as can be known, direct-action valve lifter for internal combustion engine according to the invention first aspect, because the component parts quantity of valve tappet is few, the desired tolerance of size of each component parts is loose, simultaneously, because the operation of each component parts of assembling also becomes simply, so can significantly cut down the manufacture cost of valve tappet, comes to provide at an easy rate valve tappet like this.

In addition,, when the high spinning movement of cam, also can guarantee the smooth action of tappet, decrease so can prevent the eccentric wear of valve tappet even become under the low lifting pattern of existing issue owing to the smooth action at tappet hinders; Owing to need not keep the high spring members that promotes with tappet, so needn't consider elastic force the restriction of revolution and the elastic force of spring are weakened, the degrees of freedom of engine design improves.

According to the second aspect of invention, owing to the size that can reduce on the cam slide direction of center cams, so can make valve tappet miniaturization etc. like this, the design freedom of cam and valve tappet improves.

The third aspect by invention, often be fastened on the structure in the slit of high lift cam idle running usefulness according to high lift cam, because even other rotation preventive mechanism is not set between tappet body and cylinder barrel, the tappet body is cylinder barrel spline relatively also, so the formation of such tappet body and cylinder barrel becomes succinct.

Description of drawings

Fig. 1 is the sectional view of the direct-action valve lifter for internal combustion engine periphery of one embodiment of the invention.

Fig. 2 is the sectional view that the center tappet is accommodated in this valve tappet of not corresponding with the slit of side tappet locational state.

Fig. 3 is the side view (seeing the figure of the valve tappet of representing Fig. 2 from the right side) of this valve tappet.

Fig. 4 is the exploded perspective view of this valve tappet.

Fig. 5 is the sectional view that the center tappet is accommodated in this valve tappet of the locational state corresponding with the slit of side tappet.

Fig. 6 is the sectional view of the direct-action valve lifter for internal combustion engine of second embodiment of the invention, is the figure that expression center tappet is accommodated in the locational state corresponding with the slit of side tappet.

Fig. 7 is the sectional view that expression center tappet is accommodated in not corresponding with the slit of side tappet locational state.

Fig. 8 is the sectional view of the direct-action valve lifter for internal combustion engine of third embodiment of the invention, is the figure that expression center tappet is accommodated in not corresponding with the slit of side tappet locational state.

Fig. 9 is the right side view of this valve tappet.

Figure 10 is the sectional view that expression center tappet is accommodated in the locational state corresponding with the slit of side tappet.

Figure 11 is the sectional view of existing valve tappet.

Description of reference numerals

10 cylinder heads

11 cylinder barrels

The 11a pod

11b, 11c oil circuit

14 constitute the air-breathing valve of valve actuating gear

15 valve stems

20 constitute the cam unit of valve actuating gear

22 high liftings are used center cams

24 low liftings are used the side cam

30, the straight ejector half valve stem of 30A, 30B

32 side tappets (tappet body)

32a side cam slips face

The slit of 33 center cams idle running usefulness

34 through holes

39 compression helical springs

40, the center tappet of 40A, 40B piston type

The 40a center cams is slipped face

The width of the slit of d center cams idle running usefulness

The width of t center cams (thickness of slab)

Embodiment

Below, according to embodiment embodiments of the present invention are described.

Fig. 1 to Fig. 5 represents one embodiment of the present of invention, Fig. 1 is a sectional view of using the direct-action valve lifter periphery of valve actuating gear as the formation internal-combustion engine of one embodiment of the invention, Fig. 2 is the sectional view of this valve tappet of the center tappet state that is accommodated in not corresponding with the slit of side tappet position, Fig. 3 is the side view (seeing the figure of the valve tappet of representing Fig. 2 from the right side) of this valve tappet, Fig. 4 is the exploded perspective view of this valve tappet, and Fig. 5 is the sectional view of this valve tappet of the center tappet state that is accommodated in the position corresponding with the slit of side tappet.

In these figure, reference character 12 is provided in a side of the intakeport on the cylinder head 10 of engine for automobile, reference character 14 is provided in a side of the air-breathing valve on the mouth 12, outstanding near the cylinder barrel 11 of the bar of air-breathing valve (valve stem) 15 intakeport 12, simultaneously, with compression helical spring 16 to the direction application of force that intakeport 12 is closed.

Reference character 20 is to make low the lifting with

side cam

24,24 incorporate cam unit 20 in the both sides that height promotes with center cams 22, be configured in the top of cylinder barrel 11, between cam unit 20 and valve stem 15, clamping the valve tappet 30 that can in cylinder barrel 11, slide along the vertical direction.

Valve tappet 30 is provided with along the slit 33 of the center cams 22 idle running usefulness of cam slide direction extension, mainly by constituting with lower member: have the side tappet 32 as the tappet body that an offside

cam slips face

32a, 32a at the top at the top as shown in Figure 4; The center tappet 40 of the piston type of configuration slidably in the through hole 34 that the inside and slit 33 bearing of trends of side tappet 32 are provided with orthogonally; Make center tappet 40 remain on the pressure spring 39 of assigned position.And through hole 34 is made of circular hole, center tappet 40 constitute engage with through hole 34 round-ended cylinder shape arranged, the outer circumferential face of center tappet 40 forms center cams and slips face 40a.

Reference character 36 is connectors of bringing into play function as being pressed into the spring load spare in opening side bottom that is fixed on close through hole 34 and the hole 35 that through hole 34 be arranged in parallel, the outstanding spline pin 37 that is provided with on the connector 36 that round-ended cylinder shape is arranged, spline pin 37 engages with the pod 11a of cylinder barrel 11 sides, constitutes the rotation preventive mechanism that stops the rotation of valve tappet 30 relative cylinder barrels 11 (cam 22,24).

In connector 36, there is the sliding pin 38 of round-ended cylinder shape to dispose slidably at axle direction, between connector 36 and sliding pin 38, clamped compression helical spring 39, make center tappet 40 to away from the direction of connector (left among Fig. 2 to) application of force.

Reference character 11b is provided in a side of on the cylinder head 10, with the oil circuit of position (facing the position of the center tappet 40 of the valve tappet 30) opening of the opposite side of pod 11a of cylinder barrel 11, utilization is from the pressure of the engine oil of this oil circuit 11b supply, center tappet 40 slides along through hole 34, constitutes the form of the lifting capacity switching of valve 14.

Promptly, via oil circuit 11b when the center tappet 40 effect oil pressure (high pressure), the elastic force of antagonistic spring 39 slides along through hole 34, as shown in Figure 5, when center tappet 40 becomes the position corresponding with slit 33, the high lifting with center cams 22 and center tappet 40 (the face that slips 40a) slipped, and in valve stem 15, transmits high lifting capacity via center tappet 40 and side tappet 32 (tappet body).

On the other hand, when acting on the oil pressure decline of center tappet 40, center tappet 40 utilizes the elastic force of spring 39 to turn back to not the initial position corresponding with slit 33, as shown in Figure 2, the high lifting with center cams 22 dallied in slit 33, simultaneously, the low lifting with side cam 24 and side tappet 32 (the face that slips 32a) slipped, and hangs down lifting capacity via side tappet 32 (tappet body) transmission on valve stem 15.

Like this, center tappet 40 slides along through hole 34 by the oil pressure that is acted on, and can select the state that a ground adopts the state that can slip with center cams 24 and do not slip with center cams 24.

In addition, because center tappet 40 constitutes cylindrical shape, it is arc surface that center cams is slipped face 40a, so the length of the face that the slips 40a of relative regulation lifting capacity shortens, can make like this center tappet 40 in the size of cam slide direction, be that the external diameter of center tappet 40 reduces etc., the design freedom of center cams 24 and valve tappet 30 improves.

Fig. 6 and Fig. 7 represent the direct-action valve lifter for internal combustion engine of second embodiment of the invention, Fig. 6 is the sectional view of the valve tappet of the center tappet state that is accommodated in the position corresponding with the slit of side tappet, and Fig. 7 is the valve tappet sectional view that the center tappet is accommodated in the state of not corresponding with the slit of side tappet position.

In described first embodiment, be provided with the rotation preventive mechanism of the valve tappet 30 that the pod 11a by the spline pin 37 of valve tappet 30 (side tappet 32) side and cylinder barrel 11 sides constitutes.In the present embodiment, the width d of the slit 33 of center cams idle running usefulness roughly with width (thickness of slab) the t coupling of center cams 22, because the profile of center cams 22 constitutes the shape that often engages with slit 33, so slit 33 is brought into play function as prevention valve tappet 30 relative to the rotation preventive mechanism that cylinder barrel 11 (cam unit 20) rotates with center cams 22, thereby, do not need rotation preventive mechanism such shown in first embodiment (pod 11a and spline pin 37), correspondingly make the structure of valve tappet 30A and cylinder barrel 11 become succinct thus.

In addition, in described first embodiment, piston type center tappet 40 does not act on the initial of oil pressure (high pressure) on center tappet 40, as shown in Figure 2, remain on not on the position (the low drive transmitting mode that promotes with side cam 24) corresponding, when oil pressure (high pressure) acts on the center tappet 40, as shown in Figure 5 with the elastic force of compression helical spring 39 with slit 33, center tappet 40 moves to the position corresponding with slit 33, switches to the high drive transmitting pattern that promotes with side cam 22.In this second embodiment, opposite with first embodiment's switching, piston type center tappet 40A does not act on the initial of oil pressure on the tappet 40A of center, as shown in Figure 6, utilize the elastic force of compression helical spring 39 to remain on the position (the high lifting with the driving force of side cam 22 transmitted the position) corresponding, when oil pressure acts on the center tappet 40, as shown in Figure 7 with slit 33, move to the position corresponding, switch to the low driving force transfer mode that promotes with side cam 24 with slit 33.

That is, reference character 38A is the sliding pin that round-ended cylinder shape is arranged that is configured in the hole 35, faces at valve tappet 30A on the position in sliding pin 38A (hole 35), is located at the oil circuit 11c opening on the cylinder head 10.Opposition side in the sliding pin 38A of through hole 34 configuration side, dispose the lid 44 that the outside forms sphere, simultaneously, on lid 44 and piston type center tappet 40A, clamped compression helical spring 39, center tappet 40A and sliding pin 38A butt remain on the assigned position corresponding with slit 33.

Specifically, when acting on sliding pin 38A by oil circuit 11c oil pressure (high pressure), the elastic force of antagonistic spring 39A, center tappet 40A slides along through hole 34, as shown in Figure 7, when becoming not the position corresponding with slit 33, the high lifting with center cams 22 dallied in slit 33, and simultaneously, the low lifting with side cam 24 and side tappet 32 slipped, in valve stem 15, transmit low lifting capacity by side tappet 32 (tappet body).On the other hand, when the oil pressure that acts on sliding pin 38A is descended, turn back to not the initial position corresponding with the elastic force of spring 39 with slit 33, as shown in Figure 6, the high lifting with center cams 22 slipped with center tappet 40A, transmits high lifting capacity by center tappet 40A and side tappet 32 (tappet body) on valve stem 15.

In addition, since identical with described first embodiment, so by giving the explanation that identical reference character omits its repetition.

Fig. 8 and Fig. 9 represent the direct-action valve lifter for internal combustion engine of third embodiment of the invention, Fig. 8 is the sectional view that expression center tappet is accommodated in the state of not corresponding with the slit of side tappet position, and Fig. 9 is the sectional view that expression center tappet is accommodated in the state of the position corresponding with the slit of side tappet.

The 3rd embodiment is above-mentioned first embodiment's improvement, in first embodiment, be to make the elastic force of compression helical spring 39 act on structure on the center tappet 40 of piston type by sliding pin 38, and in the 3rd embodiment, be that the outstanding connector that round-ended cylinder shape is arranged 36 that spline pin 37 is set can slide along the hole 35 of the central part that is located at through hole 34, formation is stretched out to the central part of center tappet 40B by the spring load portion 41 that is equivalent to the sliding pin that engages with this connector 36, the elastic force of compression helical spring 39 directly acts on the structure of center tappet 40B, and the number of components that constitutes valve tappet 30B like this is few.

In addition, because the elastic force of compression helical spring 39 acts on the central part of center tappet 40B, so the slip of center tappet 40B is smooth and easy.

In addition, since identical with the first above-mentioned embodiment, so by giving the explanation that identical reference character omits its repetition.

In first to the 3rd above-mentioned embodiment, through hole 34 and center tappet 40 (40A, 40B) constitute cylindrical shape, but also can constitute square.

In addition, in first to the 3rd above-mentioned embodiment, the elastic force and the oil pressure that constitute with spring make the structure of piston slip, but also can make the structure that dispenses the use of spring by the front and back that make oil pressure act on piston.

In addition, in first to the 3rd above-mentioned embodiment, the valve tappet of valve actuating gear that formation is located at the air-breathing valve of intakeport is illustrated, but the valve tappet of valve actuating gear that is located at the exhaust valve of relief opening for formation can be suitable for the present invention too.

Claims

1. direct-action valve lifter for internal combustion engine, this direct-action valve lifter is a cylindrical shape, be installed between the cam and valve stem that constitutes the engine valve driving mechanism, wherein, described cam is by with high lift cam with low lift cam is integrated constitutes, the center tappet that described valve tappet comprises the side tappet that slips for described low lift cam, slip for described high lift cam and make the tappet action of described center in order to valve lift amount is switched to the oil sector of height two-stage is characterized in that:

On the top of described columnar tappet body, be provided with along the slit of the center cams idle running usefulness of cam slide direction extension, be formed in the top and have the side tappet that low lift cam is slipped face, and, in described tappet body, be provided with along the hole of extending with the direction of described slit quadrature, the piston type center tappet that the configuration using oil pressure slides in this hole.

2. direct-action valve lifter for internal combustion engine as claimed in claim 1 is characterized in that described hole is made of circular hole, and described center tappet constitutes cylindrical shape.

3. direct-action valve lifter for internal combustion engine as claimed in claim 1 or 2 is characterized in that, described high lift cam the idle running width of slit and width (thickness of slab) approximate match of described high lift cam.